[PATCH 0/2] KVM enablement for facility bit 81 and 82

Joseph Salisbury joseph.salisbury at canonical.com
Fri Feb 2 22:54:04 UTC 2018


From: Christian Borntraeger <borntraeger at de.ibm.com>

BugLink: http://bugs.launchpad.net/bugs/1747090

== SRU Justification ==
Mainline commit 35b3fde6203b9 is a KVM patch for s390x to provide
facility bits 81 (ppa15) and 82 (bpb).  This is required for branch prediction
behaviour changes.

This is the public bug for SRU.  There is also a priave bug report:
http://bugs.launchpad.net/bugs/1743560

There is a qemu portion to this fix:
http://patchwork.ozlabs.org/cover/862801/

This fix is also requred in Artful and Bionic, but Xenial requires a prereq commit,
so it is being SRU'd separatly.

== Fixes ==
ed8dda0bf74b ("Enable all facility bits that are known good for passthrough")
35b3fde6203b ("KVM: s390: wire up bpb feature")


== Regression Potential ==
Low, this fix is limited to s390.

== Test Case ==
A test kernel was built with these patches and tested by the original bug
reporter.  The bug reporter states the test kernel resolved the bug.



Alexander Yarygin (1):
  KVM: s390: Enable all facility bits that are known good for
    passthrough

Christian Borntraeger (1):
  KVM: s390: wire up bpb feature

 arch/s390/include/asm/kvm_host.h |  3 ++-
 arch/s390/include/uapi/asm/kvm.h |  3 +++
 arch/s390/kvm/kvm-s390.c         | 16 ++++++++++++++--
 include/uapi/linux/kvm.h         |  1 +
 4 files changed, 20 insertions(+), 3 deletions(-)

-- 
2.9.4





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